Fig. 1: Chemical and physical structures of the sample.
From: Physical and chemical imaging of adhesive interfaces with soft X-rays
a Chemical structures of DGEBA, DDS, PEEK, and the curing reaction of DGEBA-DDS. b Oblique polishing. The geometrical directions of the sample before polishing (X, Y, and Z) and after polishing (Xp, Yp, and Zp) are indicated along with the corresponding illustration. Examination using an atomic force microscope (AFM) revealed hill-and-valley structures at the plasma-treated PEEK surface. Uncured DGEBA-DDS was adhered to the plasma-treated PEEK surface via the curing reaction of DGEBA-DDS. The cross-section of the DGEBA-DDS/PEEK interface was exposed by polishing the X–Y plane of the adhered sample at the oblique angle of 2°. The depth distribution along the Z direction was reflected in the Yp direction. The TFAA treatment was applied to the exposed cross-section. XRF imaging was performed at the Xp–Yp plane. c Microprobe XRF spectra (hv = 780 eV) in the regions of DGEBA-DDS and PEEK. A soft X-ray beam from SPring-8 synchrotron radiation was focused by the Fresnel zone plate (FZP) and the order sorting aperture (OSA). XRF spectra were measured using a silicon drift detector (SDD). The XRF image was obtained by scanning the sample in the Xp and Yp directions.
